2015-11-11 22:32:35

by Akshay Bhat

[permalink] [raw]
Subject: [PATCH] rtc: Add Epson RX8010SJ RTC driver

This driver supports the following functions:
- reading and setting time
- alarms when connected to an IRQ
- reading and clearing the voltage low flags

Datasheet:
http://www.epsondevice.com/docs/qd/en/DownloadServlet?id=ID000956
Signed-off-by: Akshay Bhat <[email protected]>
---
drivers/rtc/Kconfig | 10 +
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-rx8010.c | 570 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 581 insertions(+)
create mode 100644 drivers/rtc/rtc-rx8010.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 2a52424..376322f 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -558,6 +558,16 @@ config RTC_DRV_FM3130
This driver can also be built as a module. If so the module
will be called rtc-fm3130.

+config RTC_DRV_RX8010
+ tristate "Epson RX8010SJ"
+ depends on I2C
+ help
+ If you say yes here you get support for the Epson RX8010SJ RTC
+ chip.
+
+ This driver can also be built as a module. If so, the module
+ will be called rtc-rx8010.
+
config RTC_DRV_RX8581
tristate "Epson RX-8581"
help
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 231f764..62d61b2 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -128,6 +128,7 @@ obj-$(CONFIG_RTC_DRV_RS5C372) += rtc-rs5c372.o
obj-$(CONFIG_RTC_DRV_RV3029C2) += rtc-rv3029c2.o
obj-$(CONFIG_RTC_DRV_RV8803) += rtc-rv8803.o
obj-$(CONFIG_RTC_DRV_RX4581) += rtc-rx4581.o
+obj-$(CONFIG_RTC_DRV_RX8010) += rtc-rx8010.o
obj-$(CONFIG_RTC_DRV_RX8025) += rtc-rx8025.o
obj-$(CONFIG_RTC_DRV_RX8581) += rtc-rx8581.o
obj-$(CONFIG_RTC_DRV_S35390A) += rtc-s35390a.o
diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
new file mode 100644
index 0000000..9b8bd76
--- /dev/null
+++ b/drivers/rtc/rtc-rx8010.c
@@ -0,0 +1,570 @@
+/*
+ * Driver for the Epson RTC module RX-8010 SJ
+ *
+ * Copyright(C) Timesys Corporation 2015
+ * Copyright(C) General Electric Company 2015
+ * Copyright(C) SEIKO EPSON CORPORATION 2013. All rights reserved.
+ *
+ * Derived from RX-8025 driver:
+ * Copyright (C) 2009 Wolfgang Grandegger <[email protected]>
+ *
+ * Copyright (C) 2005 by Digi International Inc.
+ * All rights reserved.
+ *
+ * Modified by fengjh at rising.com.cn
+ * <http://lists.lm-sensors.org/mailman/listinfo/lm-sensors>
+ * 2006.11
+ *
+ * Code cleanup by Sergei Poselenov, <[email protected]>
+ * Converted to new style by Wolfgang Grandegger <[email protected]>
+ * Alarm and periodic interrupt added by Dmitry Rakhchev <[email protected]>
+ *
+ * This driver software is distributed as is, without any warranty of any kind,
+ * either express or implied as further specified in the GNU Public License.
+ * This software may be used and distributed according to the terms of the GNU
+ * Public License, version 2 as published by the Free Software Foundation.
+ * See the file COPYING in the main directory of this archive for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/bcd.h>
+#include <linux/bitops.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rtc.h>
+
+#define RX8010_SEC 0x10
+#define RX8010_MIN 0x11
+#define RX8010_HOUR 0x12
+#define RX8010_WDAY 0x13
+#define RX8010_MDAY 0x14
+#define RX8010_MONTH 0x15
+#define RX8010_YEAR 0x16
+#define RX8010_YEAR 0x16
+#define RX8010_RESV17 0x17
+#define RX8010_ALMIN 0x18
+#define RX8010_ALHOUR 0x19
+#define RX8010_ALWDAY 0x1A
+#define RX8010_TCOUNT0 0x1B
+#define RX8010_TCOUNT1 0x1C
+#define RX8010_EXT 0x1D
+#define RX8010_FLAG 0x1E
+#define RX8010_CTRL 0x1F
+/* 0x20 to 0x2F are user registers */
+#define RX8010_RESV30 0x30
+#define RX8010_RESV31 0x32
+#define RX8010_IRQ 0x32
+
+#define RX8010_EXT_WADA BIT(3)
+
+#define RX8010_FLAG_VLF BIT(1)
+#define RX8010_FLAG_AF BIT(3)
+#define RX8010_FLAG_TF BIT(4)
+#define RX8010_FLAG_UF BIT(5)
+
+#define RX8010_CTRL_AIE BIT(3)
+#define RX8010_CTRL_UIE BIT(5)
+#define RX8010_CTRL_STOP BIT(6)
+#define RX8010_CTRL_TEST BIT(7)
+
+#define RX8010_ALARM_AE BIT(7)
+
+static const struct i2c_device_id rx8010_id[] = {
+ { "rx8010", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, rx8010_id);
+
+struct rx8010_data {
+ struct i2c_client *client;
+ struct rtc_device *rtc;
+ u8 ctrlreg;
+ spinlock_t flags_lock;
+};
+
+static int rx8010_read_reg(struct i2c_client *client, int number, u8 *value)
+{
+ int ret = i2c_smbus_read_byte_data(client, number);
+
+ if (ret < 0)
+ return ret;
+
+ *value = ret;
+ return 0;
+}
+
+static int rx8010_read_regs(struct i2c_client *client, int number, u8 length,
+ u8 *values)
+{
+ int ret = i2c_smbus_read_i2c_block_data(client, number, length, values);
+
+ if (ret != length)
+ return ret < 0 ? ret : -EIO;
+
+ return 0;
+}
+
+static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)
+{
+ struct i2c_client *client = dev_id;
+ struct rx8010_data *rx8010 = i2c_get_clientdata(client);
+ u8 flagreg;
+
+ spin_lock(&rx8010->flags_lock);
+
+ if (rx8010_read_reg(client, RX8010_FLAG, &flagreg)) {
+ spin_unlock(&rx8010->flags_lock);
+ return IRQ_NONE;
+ }
+
+ if (flagreg & RX8010_FLAG_VLF)
+ dev_warn(&client->dev, "Frequency stop detected\n");
+
+ if (flagreg & RX8010_FLAG_TF) {
+ flagreg &= ~RX8010_FLAG_TF;
+ rtc_update_irq(rx8010->rtc, 1, RTC_PF | RTC_IRQF);
+ }
+
+ if (flagreg & RX8010_FLAG_AF) {
+ flagreg &= ~RX8010_FLAG_AF;
+ rtc_update_irq(rx8010->rtc, 1, RTC_AF | RTC_IRQF);
+ }
+
+ if (flagreg & RX8010_FLAG_UF) {
+ flagreg &= ~RX8010_FLAG_UF;
+ rtc_update_irq(rx8010->rtc, 1, RTC_UF | RTC_IRQF);
+ }
+
+ i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);
+
+ spin_unlock(&rx8010->flags_lock);
+ return IRQ_HANDLED;
+}
+
+static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
+{
+ struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+ u8 date[7];
+ u8 flagreg;
+ int err;
+
+ err = rx8010_read_reg(rx8010->client, RX8010_FLAG, &flagreg);
+ if (err)
+ return err;
+
+ if (flagreg & RX8010_FLAG_VLF) {
+ dev_warn(dev, "Frequency stop detected\n");
+ return -EINVAL;
+ }
+
+ err = rx8010_read_regs(rx8010->client, RX8010_SEC, 7, date);
+ if (err)
+ return err;
+
+ dt->tm_sec = bcd2bin(date[RX8010_SEC-RX8010_SEC] & 0x7f);
+ dt->tm_min = bcd2bin(date[RX8010_MIN-RX8010_SEC] & 0x7f);
+ dt->tm_hour = bcd2bin(date[RX8010_HOUR-RX8010_SEC] & 0x3f);
+ dt->tm_mday = bcd2bin(date[RX8010_MDAY-RX8010_SEC] & 0x3f);
+ dt->tm_mon = bcd2bin(date[RX8010_MONTH-RX8010_SEC] & 0x1f) - 1;
+ dt->tm_year = bcd2bin(date[RX8010_YEAR-RX8010_SEC]);
+ dt->tm_wday = bcd2bin(date[RX8010_WDAY-RX8010_SEC] & 0x7f);
+
+ if (dt->tm_year < 70)
+ dt->tm_year += 100;
+
+ return rtc_valid_tm(dt);
+}
+
+static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
+{
+ struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+ u8 date[7];
+ u8 ctrl, flagreg;
+ int ret;
+ unsigned long irqflags;
+
+ /* BUG: The HW assumes every year that is a multiple of 4 to be a leap
+ * year. Next time this is wrong is 2100, which will not be a leap
+ * year.
+ */
+
+ /* set STOP bit before changing clock/calendar */
+ ret = rx8010_read_reg(rx8010->client, RX8010_CTRL, &ctrl);
+ if (ret)
+ return ret;
+ rx8010->ctrlreg = ctrl | RX8010_CTRL_STOP;
+ ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
+ rx8010->ctrlreg);
+ if (ret < 0)
+ return ret;
+
+ date[RX8010_SEC-RX8010_SEC] = bin2bcd(dt->tm_sec);
+ date[RX8010_MIN-RX8010_SEC] = bin2bcd(dt->tm_min);
+ date[RX8010_HOUR-RX8010_SEC] = bin2bcd(dt->tm_hour);
+ date[RX8010_MDAY-RX8010_SEC] = bin2bcd(dt->tm_mday);
+ date[RX8010_MONTH-RX8010_SEC] = bin2bcd(dt->tm_mon + 1);
+ date[RX8010_YEAR-RX8010_SEC] = bin2bcd(dt->tm_year % 100);
+ date[RX8010_WDAY-RX8010_SEC] = bin2bcd(dt->tm_wday);
+
+ ret = i2c_smbus_write_i2c_block_data(rx8010->client,
+ RX8010_SEC, 7, date);
+ if (ret < 0)
+ return ret;
+
+ /* clear STOP bit after changing clock/calendar */
+ ret = rx8010_read_reg(rx8010->client, RX8010_CTRL, &ctrl);
+ if (ret)
+ return ret;
+ rx8010->ctrlreg = ctrl & ~RX8010_CTRL_STOP;
+ ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
+ rx8010->ctrlreg);
+ if (ret < 0)
+ return ret;
+
+ spin_lock_irqsave(&rx8010->flags_lock, irqflags);
+
+ ret = rx8010_read_reg(rx8010->client, RX8010_FLAG, &flagreg);
+ if (ret) {
+ spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
+ return ret;
+ }
+
+ if (flagreg & RX8010_FLAG_VLF)
+ ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG,
+ flagreg & ~RX8010_FLAG_VLF);
+
+ spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
+
+ return 0;
+}
+
+static int rx8010_init_client(struct i2c_client *client)
+{
+ struct rx8010_data *rx8010 = i2c_get_clientdata(client);
+ u8 ctrl[3];
+ int need_clear = 0, need_reset = 0, err = 0;
+
+ /* Initialize reserved registers as specified in datasheet */
+ err = i2c_smbus_write_byte_data(client, RX8010_RESV17, 0xD8);
+ if (err < 0)
+ return err;
+
+ err = i2c_smbus_write_byte_data(client, RX8010_RESV30, 0x00);
+ if (err < 0)
+ return err;
+
+ err = i2c_smbus_write_byte_data(client, RX8010_RESV31, 0x08);
+ if (err < 0)
+ return err;
+
+ err = i2c_smbus_write_byte_data(client, RX8010_IRQ, 0x00);
+ if (err < 0)
+ return err;
+
+ err = rx8010_read_regs(rx8010->client, RX8010_EXT, 3, ctrl);
+ if (err)
+ return err;
+
+ if ((ctrl[1] & RX8010_FLAG_VLF)) {
+ dev_warn(&client->dev, "Frequency stop was detected\n");
+ need_reset = 1;
+ }
+
+ if (ctrl[1] & RX8010_FLAG_AF) {
+ dev_warn(&client->dev, "Alarm was detected\n");
+ need_clear = 1;
+ }
+
+ if (ctrl[1] & RX8010_FLAG_TF)
+ need_clear = 1;
+
+ if (ctrl[1] & RX8010_FLAG_UF)
+ need_clear = 1;
+
+ if (need_reset) {
+ ctrl[0] = ctrl[1] = ctrl[2] = 0;
+ err = i2c_smbus_write_i2c_block_data(client, RX8010_EXT,
+ 3, ctrl);
+ if (err < 0)
+ return err;
+ } else if (need_clear) {
+ err = i2c_smbus_write_byte_data(client, RX8010_FLAG, 0x00);
+ if (err < 0)
+ return err;
+ }
+
+ rx8010->ctrlreg = (ctrl[2] & ~RX8010_CTRL_TEST);
+
+ return err;
+}
+
+static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+ struct i2c_client *client = rx8010->client;
+ u8 alarmvals[3];
+ u8 flagreg;
+ int err;
+
+ err = rx8010_read_regs(client, RX8010_ALMIN, 3, alarmvals);
+ if (err)
+ return err;
+
+ err = rx8010_read_reg(client, RX8010_FLAG, &flagreg);
+ if (err)
+ return err;
+
+ t->time.tm_sec = 0;
+ t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
+ t->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
+
+ if (alarmvals[2] & RX8010_ALARM_AE)
+ t->time.tm_mday = -1;
+ else
+ t->time.tm_mday = bcd2bin(alarmvals[2] & 0x7f);
+
+ t->time.tm_wday = -1;
+ t->time.tm_mon = -1;
+ t->time.tm_year = -1;
+
+ t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE);
+ t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled;
+
+ return err;
+}
+
+static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+ u8 alarmvals[3];
+ u8 extreg, flagreg;
+ int err;
+ unsigned long irqflags;
+
+ spin_lock_irqsave(&rx8010->flags_lock, irqflags);
+ err = rx8010_read_reg(client, RX8010_FLAG, &flagreg);
+ if (err) {
+ spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
+ return err;
+ }
+
+ if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) {
+ rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
+ err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
+ rx8010->ctrlreg);
+ if (err < 0) {
+ spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
+ return err;
+ }
+ }
+
+ flagreg &= ~RX8010_FLAG_AF;
+ err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);
+ spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
+ if (err < 0)
+ return err;
+
+ alarmvals[0] = bin2bcd(t->time.tm_min);
+ alarmvals[1] = bin2bcd(t->time.tm_hour);
+ alarmvals[2] = bin2bcd(t->time.tm_mday);
+
+ err = i2c_smbus_write_i2c_block_data(rx8010->client, RX8010_ALMIN,
+ 2, alarmvals);
+ if (err < 0)
+ return err;
+
+ err = rx8010_read_reg(client, RX8010_EXT, &extreg);
+ if (err)
+ return err;
+
+ extreg |= RX8010_EXT_WADA;
+ err = i2c_smbus_write_byte_data(rx8010->client, RX8010_EXT, extreg);
+ if (err < 0)
+ return err;
+
+ if (alarmvals[2] == 0)
+ alarmvals[2] |= RX8010_ALARM_AE;
+
+ err = i2c_smbus_write_byte_data(rx8010->client, RX8010_ALWDAY,
+ alarmvals[2]);
+ if (err < 0)
+ return err;
+
+ if (t->enabled) {
+ if (rx8010->rtc->uie_rtctimer.enabled)
+ rx8010->ctrlreg |= RX8010_CTRL_UIE;
+ if (rx8010->rtc->aie_timer.enabled)
+ rx8010->ctrlreg |=
+ (RX8010_CTRL_AIE | RX8010_CTRL_UIE);
+
+ err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
+ rx8010->ctrlreg);
+ if (err < 0)
+ return err;
+ }
+
+ return 0;
+}
+
+static int rx8010_alarm_irq_enable(struct device *dev,
+ unsigned int enabled)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+ u8 flagreg;
+ u8 ctrl;
+ int err;
+
+ ctrl = rx8010->ctrlreg;
+
+ if (enabled) {
+ if (rx8010->rtc->uie_rtctimer.enabled)
+ ctrl |= RX8010_CTRL_UIE;
+ if (rx8010->rtc->aie_timer.enabled)
+ ctrl |= (RX8010_CTRL_AIE | RX8010_CTRL_UIE);
+ } else {
+ if (!rx8010->rtc->uie_rtctimer.enabled)
+ ctrl &= ~RX8010_CTRL_UIE;
+ if (!rx8010->rtc->aie_timer.enabled)
+ ctrl &= ~RX8010_CTRL_AIE;
+ }
+
+ err = rx8010_read_reg(client, RX8010_FLAG, &flagreg);
+ if (err)
+ return err;
+ flagreg &= ~RX8010_FLAG_AF;
+ err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);
+ if (err < 0)
+ return err;
+
+ if (ctrl != rx8010->ctrlreg) {
+ rx8010->ctrlreg = ctrl;
+ err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
+ rx8010->ctrlreg);
+ if (err < 0)
+ return err;
+ }
+
+ return 0;
+}
+
+static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+ int ret, tmp;
+ u8 flagreg;
+ unsigned long irqflags;
+
+ switch (cmd) {
+ case RTC_VL_READ:
+ ret = rx8010_read_reg(rx8010->client, RX8010_FLAG, &flagreg);
+ if (ret)
+ return ret;
+
+ tmp = !!(flagreg & RX8010_FLAG_VLF);
+ if (copy_to_user((void __user *)arg, &tmp, sizeof(int)))
+ return -EFAULT;
+
+ return 0;
+
+ case RTC_VL_CLR:
+ spin_lock_irqsave(&rx8010->flags_lock, irqflags);
+ ret = rx8010_read_reg(rx8010->client, RX8010_FLAG, &flagreg);
+ if (ret < 0) {
+ spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
+ return ret;
+ }
+
+ flagreg &= ~RX8010_FLAG_VLF;
+ ret = i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);
+ spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+
+static struct rtc_class_ops rx8010_rtc_ops = {
+ .read_time = rx8010_get_time,
+ .set_time = rx8010_set_time,
+ .ioctl = rx8010_ioctl,
+};
+
+static int rx8010_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+ struct rx8010_data *rx8010;
+ int err = 0;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
+ | I2C_FUNC_SMBUS_I2C_BLOCK)) {
+ dev_err(&adapter->dev, "doesn't support required functionality\n");
+ return -EIO;
+ }
+
+ rx8010 = devm_kzalloc(&client->dev, sizeof(struct rx8010_data),
+ GFP_KERNEL);
+ if (!rx8010)
+ return -ENOMEM;
+
+ rx8010->client = client;
+ i2c_set_clientdata(client, rx8010);
+
+ spin_lock_init(&rx8010->flags_lock);
+
+ err = rx8010_init_client(client);
+ if (err)
+ return err;
+
+ if (client->irq > 0) {
+ dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
+ err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
+ rx8010_irq_1_handler, IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+ "rx8010", client);
+
+ if (err) {
+ dev_err(&client->dev, "unable to request IRQ\n");
+ client->irq = 0;
+ } else {
+ rx8010_rtc_ops.read_alarm = rx8010_read_alarm;
+ rx8010_rtc_ops.set_alarm = rx8010_set_alarm;
+ rx8010_rtc_ops.alarm_irq_enable = rx8010_alarm_irq_enable;
+ }
+ }
+
+ rx8010->rtc = devm_rtc_device_register(&client->dev, client->name,
+ &rx8010_rtc_ops, THIS_MODULE);
+
+ if (IS_ERR(rx8010->rtc)) {
+ dev_err(&client->dev, "unable to register the class device\n");
+ return PTR_ERR(rx8010->rtc);
+ }
+
+ rx8010->rtc->max_user_freq = 1;
+
+ return err;
+}
+
+static struct i2c_driver rx8010_driver = {
+ .driver = {
+ .name = "rtc-rx8010",
+ },
+ .probe = rx8010_probe,
+ .id_table = rx8010_id,
+};
+
+module_i2c_driver(rx8010_driver);
+
+MODULE_AUTHOR("Akshay Bhat <[email protected]>");
+MODULE_DESCRIPTION("Epson RX8010SJ RTC driver");
+MODULE_LICENSE("GPL");
--
2.6.3


2015-12-01 16:00:21

by Akshay Bhat

[permalink] [raw]
Subject: Re: [PATCH] rtc: Add Epson RX8010SJ RTC driver

Hi,

Wanted to check if there was any feedback on this patch?

Thanks,
Akshay

On 11/11/2015 05:31 PM, Akshay Bhat wrote:
> This driver supports the following functions:
> - reading and setting time
> - alarms when connected to an IRQ
> - reading and clearing the voltage low flags
>
> Datasheet:
> http://www.epsondevice.com/docs/qd/en/DownloadServlet?id=ID000956
> Signed-off-by: Akshay Bhat <[email protected]>
> ---
> drivers/rtc/Kconfig | 10 +
> drivers/rtc/Makefile | 1 +
> drivers/rtc/rtc-rx8010.c | 570 +++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 581 insertions(+)
> create mode 100644 drivers/rtc/rtc-rx8010.c
>
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index 2a52424..376322f 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -558,6 +558,16 @@ config RTC_DRV_FM3130
> This driver can also be built as a module. If so the module
> will be called rtc-fm3130.
>
> +config RTC_DRV_RX8010
> + tristate "Epson RX8010SJ"
> + depends on I2C
> + help
> + If you say yes here you get support for the Epson RX8010SJ RTC
> + chip.
> +
> + This driver can also be built as a module. If so, the module
> + will be called rtc-rx8010.
> +
> config RTC_DRV_RX8581
> tristate "Epson RX-8581"
> help
> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> index 231f764..62d61b2 100644
> --- a/drivers/rtc/Makefile
> +++ b/drivers/rtc/Makefile
> @@ -128,6 +128,7 @@ obj-$(CONFIG_RTC_DRV_RS5C372) += rtc-rs5c372.o
> obj-$(CONFIG_RTC_DRV_RV3029C2) += rtc-rv3029c2.o
> obj-$(CONFIG_RTC_DRV_RV8803) += rtc-rv8803.o
> obj-$(CONFIG_RTC_DRV_RX4581) += rtc-rx4581.o
> +obj-$(CONFIG_RTC_DRV_RX8010) += rtc-rx8010.o
> obj-$(CONFIG_RTC_DRV_RX8025) += rtc-rx8025.o
> obj-$(CONFIG_RTC_DRV_RX8581) += rtc-rx8581.o
> obj-$(CONFIG_RTC_DRV_S35390A) += rtc-s35390a.o
> diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
> new file mode 100644
> index 0000000..9b8bd76
> --- /dev/null
> +++ b/drivers/rtc/rtc-rx8010.c
> @@ -0,0 +1,570 @@
> +/*
> + * Driver for the Epson RTC module RX-8010 SJ
> + *
> + * Copyright(C) Timesys Corporation 2015
> + * Copyright(C) General Electric Company 2015
> + * Copyright(C) SEIKO EPSON CORPORATION 2013. All rights reserved.
> + *
> + * Derived from RX-8025 driver:
> + * Copyright (C) 2009 Wolfgang Grandegger <[email protected]>
> + *
> + * Copyright (C) 2005 by Digi International Inc.
> + * All rights reserved.
> + *
> + * Modified by fengjh at rising.com.cn
> + * <http://lists.lm-sensors.org/mailman/listinfo/lm-sensors>
> + * 2006.11
> + *
> + * Code cleanup by Sergei Poselenov, <[email protected]>
> + * Converted to new style by Wolfgang Grandegger <[email protected]>
> + * Alarm and periodic interrupt added by Dmitry Rakhchev <[email protected]>
> + *
> + * This driver software is distributed as is, without any warranty of any kind,
> + * either express or implied as further specified in the GNU Public License.
> + * This software may be used and distributed according to the terms of the GNU
> + * Public License, version 2 as published by the Free Software Foundation.
> + * See the file COPYING in the main directory of this archive for more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/bcd.h>
> +#include <linux/bitops.h>
> +#include <linux/i2c.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/rtc.h>
> +
> +#define RX8010_SEC 0x10
> +#define RX8010_MIN 0x11
> +#define RX8010_HOUR 0x12
> +#define RX8010_WDAY 0x13
> +#define RX8010_MDAY 0x14
> +#define RX8010_MONTH 0x15
> +#define RX8010_YEAR 0x16
> +#define RX8010_YEAR 0x16
> +#define RX8010_RESV17 0x17
> +#define RX8010_ALMIN 0x18
> +#define RX8010_ALHOUR 0x19
> +#define RX8010_ALWDAY 0x1A
> +#define RX8010_TCOUNT0 0x1B
> +#define RX8010_TCOUNT1 0x1C
> +#define RX8010_EXT 0x1D
> +#define RX8010_FLAG 0x1E
> +#define RX8010_CTRL 0x1F
> +/* 0x20 to 0x2F are user registers */
> +#define RX8010_RESV30 0x30
> +#define RX8010_RESV31 0x32
> +#define RX8010_IRQ 0x32
> +
> +#define RX8010_EXT_WADA BIT(3)
> +
> +#define RX8010_FLAG_VLF BIT(1)
> +#define RX8010_FLAG_AF BIT(3)
> +#define RX8010_FLAG_TF BIT(4)
> +#define RX8010_FLAG_UF BIT(5)
> +
> +#define RX8010_CTRL_AIE BIT(3)
> +#define RX8010_CTRL_UIE BIT(5)
> +#define RX8010_CTRL_STOP BIT(6)
> +#define RX8010_CTRL_TEST BIT(7)
> +
> +#define RX8010_ALARM_AE BIT(7)
> +
> +static const struct i2c_device_id rx8010_id[] = {
> + { "rx8010", 0 },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, rx8010_id);
> +
> +struct rx8010_data {
> + struct i2c_client *client;
> + struct rtc_device *rtc;
> + u8 ctrlreg;
> + spinlock_t flags_lock;
> +};
> +
> +static int rx8010_read_reg(struct i2c_client *client, int number, u8 *value)
> +{
> + int ret = i2c_smbus_read_byte_data(client, number);
> +
> + if (ret < 0)
> + return ret;
> +
> + *value = ret;
> + return 0;
> +}
> +
> +static int rx8010_read_regs(struct i2c_client *client, int number, u8 length,
> + u8 *values)
> +{
> + int ret = i2c_smbus_read_i2c_block_data(client, number, length, values);
> +
> + if (ret != length)
> + return ret < 0 ? ret : -EIO;
> +
> + return 0;
> +}
> +
> +static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)
> +{
> + struct i2c_client *client = dev_id;
> + struct rx8010_data *rx8010 = i2c_get_clientdata(client);
> + u8 flagreg;
> +
> + spin_lock(&rx8010->flags_lock);
> +
> + if (rx8010_read_reg(client, RX8010_FLAG, &flagreg)) {
> + spin_unlock(&rx8010->flags_lock);
> + return IRQ_NONE;
> + }
> +
> + if (flagreg & RX8010_FLAG_VLF)
> + dev_warn(&client->dev, "Frequency stop detected\n");
> +
> + if (flagreg & RX8010_FLAG_TF) {
> + flagreg &= ~RX8010_FLAG_TF;
> + rtc_update_irq(rx8010->rtc, 1, RTC_PF | RTC_IRQF);
> + }
> +
> + if (flagreg & RX8010_FLAG_AF) {
> + flagreg &= ~RX8010_FLAG_AF;
> + rtc_update_irq(rx8010->rtc, 1, RTC_AF | RTC_IRQF);
> + }
> +
> + if (flagreg & RX8010_FLAG_UF) {
> + flagreg &= ~RX8010_FLAG_UF;
> + rtc_update_irq(rx8010->rtc, 1, RTC_UF | RTC_IRQF);
> + }
> +
> + i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);
> +
> + spin_unlock(&rx8010->flags_lock);
> + return IRQ_HANDLED;
> +}
> +
> +static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
> +{
> + struct rx8010_data *rx8010 = dev_get_drvdata(dev);
> + u8 date[7];
> + u8 flagreg;
> + int err;
> +
> + err = rx8010_read_reg(rx8010->client, RX8010_FLAG, &flagreg);
> + if (err)
> + return err;
> +
> + if (flagreg & RX8010_FLAG_VLF) {
> + dev_warn(dev, "Frequency stop detected\n");
> + return -EINVAL;
> + }
> +
> + err = rx8010_read_regs(rx8010->client, RX8010_SEC, 7, date);
> + if (err)
> + return err;
> +
> + dt->tm_sec = bcd2bin(date[RX8010_SEC-RX8010_SEC] & 0x7f);
> + dt->tm_min = bcd2bin(date[RX8010_MIN-RX8010_SEC] & 0x7f);
> + dt->tm_hour = bcd2bin(date[RX8010_HOUR-RX8010_SEC] & 0x3f);
> + dt->tm_mday = bcd2bin(date[RX8010_MDAY-RX8010_SEC] & 0x3f);
> + dt->tm_mon = bcd2bin(date[RX8010_MONTH-RX8010_SEC] & 0x1f) - 1;
> + dt->tm_year = bcd2bin(date[RX8010_YEAR-RX8010_SEC]);
> + dt->tm_wday = bcd2bin(date[RX8010_WDAY-RX8010_SEC] & 0x7f);
> +
> + if (dt->tm_year < 70)
> + dt->tm_year += 100;
> +
> + return rtc_valid_tm(dt);
> +}
> +
> +static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
> +{
> + struct rx8010_data *rx8010 = dev_get_drvdata(dev);
> + u8 date[7];
> + u8 ctrl, flagreg;
> + int ret;
> + unsigned long irqflags;
> +
> + /* BUG: The HW assumes every year that is a multiple of 4 to be a leap
> + * year. Next time this is wrong is 2100, which will not be a leap
> + * year.
> + */
> +
> + /* set STOP bit before changing clock/calendar */
> + ret = rx8010_read_reg(rx8010->client, RX8010_CTRL, &ctrl);
> + if (ret)
> + return ret;
> + rx8010->ctrlreg = ctrl | RX8010_CTRL_STOP;
> + ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
> + rx8010->ctrlreg);
> + if (ret < 0)
> + return ret;
> +
> + date[RX8010_SEC-RX8010_SEC] = bin2bcd(dt->tm_sec);
> + date[RX8010_MIN-RX8010_SEC] = bin2bcd(dt->tm_min);
> + date[RX8010_HOUR-RX8010_SEC] = bin2bcd(dt->tm_hour);
> + date[RX8010_MDAY-RX8010_SEC] = bin2bcd(dt->tm_mday);
> + date[RX8010_MONTH-RX8010_SEC] = bin2bcd(dt->tm_mon + 1);
> + date[RX8010_YEAR-RX8010_SEC] = bin2bcd(dt->tm_year % 100);
> + date[RX8010_WDAY-RX8010_SEC] = bin2bcd(dt->tm_wday);
> +
> + ret = i2c_smbus_write_i2c_block_data(rx8010->client,
> + RX8010_SEC, 7, date);
> + if (ret < 0)
> + return ret;
> +
> + /* clear STOP bit after changing clock/calendar */
> + ret = rx8010_read_reg(rx8010->client, RX8010_CTRL, &ctrl);
> + if (ret)
> + return ret;
> + rx8010->ctrlreg = ctrl & ~RX8010_CTRL_STOP;
> + ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
> + rx8010->ctrlreg);
> + if (ret < 0)
> + return ret;
> +
> + spin_lock_irqsave(&rx8010->flags_lock, irqflags);
> +
> + ret = rx8010_read_reg(rx8010->client, RX8010_FLAG, &flagreg);
> + if (ret) {
> + spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
> + return ret;
> + }
> +
> + if (flagreg & RX8010_FLAG_VLF)
> + ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG,
> + flagreg & ~RX8010_FLAG_VLF);
> +
> + spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
> +
> + return 0;
> +}
> +
> +static int rx8010_init_client(struct i2c_client *client)
> +{
> + struct rx8010_data *rx8010 = i2c_get_clientdata(client);
> + u8 ctrl[3];
> + int need_clear = 0, need_reset = 0, err = 0;
> +
> + /* Initialize reserved registers as specified in datasheet */
> + err = i2c_smbus_write_byte_data(client, RX8010_RESV17, 0xD8);
> + if (err < 0)
> + return err;
> +
> + err = i2c_smbus_write_byte_data(client, RX8010_RESV30, 0x00);
> + if (err < 0)
> + return err;
> +
> + err = i2c_smbus_write_byte_data(client, RX8010_RESV31, 0x08);
> + if (err < 0)
> + return err;
> +
> + err = i2c_smbus_write_byte_data(client, RX8010_IRQ, 0x00);
> + if (err < 0)
> + return err;
> +
> + err = rx8010_read_regs(rx8010->client, RX8010_EXT, 3, ctrl);
> + if (err)
> + return err;
> +
> + if ((ctrl[1] & RX8010_FLAG_VLF)) {
> + dev_warn(&client->dev, "Frequency stop was detected\n");
> + need_reset = 1;
> + }
> +
> + if (ctrl[1] & RX8010_FLAG_AF) {
> + dev_warn(&client->dev, "Alarm was detected\n");
> + need_clear = 1;
> + }
> +
> + if (ctrl[1] & RX8010_FLAG_TF)
> + need_clear = 1;
> +
> + if (ctrl[1] & RX8010_FLAG_UF)
> + need_clear = 1;
> +
> + if (need_reset) {
> + ctrl[0] = ctrl[1] = ctrl[2] = 0;
> + err = i2c_smbus_write_i2c_block_data(client, RX8010_EXT,
> + 3, ctrl);
> + if (err < 0)
> + return err;
> + } else if (need_clear) {
> + err = i2c_smbus_write_byte_data(client, RX8010_FLAG, 0x00);
> + if (err < 0)
> + return err;
> + }
> +
> + rx8010->ctrlreg = (ctrl[2] & ~RX8010_CTRL_TEST);
> +
> + return err;
> +}
> +
> +static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t)
> +{
> + struct rx8010_data *rx8010 = dev_get_drvdata(dev);
> + struct i2c_client *client = rx8010->client;
> + u8 alarmvals[3];
> + u8 flagreg;
> + int err;
> +
> + err = rx8010_read_regs(client, RX8010_ALMIN, 3, alarmvals);
> + if (err)
> + return err;
> +
> + err = rx8010_read_reg(client, RX8010_FLAG, &flagreg);
> + if (err)
> + return err;
> +
> + t->time.tm_sec = 0;
> + t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
> + t->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
> +
> + if (alarmvals[2] & RX8010_ALARM_AE)
> + t->time.tm_mday = -1;
> + else
> + t->time.tm_mday = bcd2bin(alarmvals[2] & 0x7f);
> +
> + t->time.tm_wday = -1;
> + t->time.tm_mon = -1;
> + t->time.tm_year = -1;
> +
> + t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE);
> + t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled;
> +
> + return err;
> +}
> +
> +static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct rx8010_data *rx8010 = dev_get_drvdata(dev);
> + u8 alarmvals[3];
> + u8 extreg, flagreg;
> + int err;
> + unsigned long irqflags;
> +
> + spin_lock_irqsave(&rx8010->flags_lock, irqflags);
> + err = rx8010_read_reg(client, RX8010_FLAG, &flagreg);
> + if (err) {
> + spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
> + return err;
> + }
> +
> + if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) {
> + rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
> + err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
> + rx8010->ctrlreg);
> + if (err < 0) {
> + spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
> + return err;
> + }
> + }
> +
> + flagreg &= ~RX8010_FLAG_AF;
> + err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);
> + spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
> + if (err < 0)
> + return err;
> +
> + alarmvals[0] = bin2bcd(t->time.tm_min);
> + alarmvals[1] = bin2bcd(t->time.tm_hour);
> + alarmvals[2] = bin2bcd(t->time.tm_mday);
> +
> + err = i2c_smbus_write_i2c_block_data(rx8010->client, RX8010_ALMIN,
> + 2, alarmvals);
> + if (err < 0)
> + return err;
> +
> + err = rx8010_read_reg(client, RX8010_EXT, &extreg);
> + if (err)
> + return err;
> +
> + extreg |= RX8010_EXT_WADA;
> + err = i2c_smbus_write_byte_data(rx8010->client, RX8010_EXT, extreg);
> + if (err < 0)
> + return err;
> +
> + if (alarmvals[2] == 0)
> + alarmvals[2] |= RX8010_ALARM_AE;
> +
> + err = i2c_smbus_write_byte_data(rx8010->client, RX8010_ALWDAY,
> + alarmvals[2]);
> + if (err < 0)
> + return err;
> +
> + if (t->enabled) {
> + if (rx8010->rtc->uie_rtctimer.enabled)
> + rx8010->ctrlreg |= RX8010_CTRL_UIE;
> + if (rx8010->rtc->aie_timer.enabled)
> + rx8010->ctrlreg |=
> + (RX8010_CTRL_AIE | RX8010_CTRL_UIE);
> +
> + err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
> + rx8010->ctrlreg);
> + if (err < 0)
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +static int rx8010_alarm_irq_enable(struct device *dev,
> + unsigned int enabled)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct rx8010_data *rx8010 = dev_get_drvdata(dev);
> + u8 flagreg;
> + u8 ctrl;
> + int err;
> +
> + ctrl = rx8010->ctrlreg;
> +
> + if (enabled) {
> + if (rx8010->rtc->uie_rtctimer.enabled)
> + ctrl |= RX8010_CTRL_UIE;
> + if (rx8010->rtc->aie_timer.enabled)
> + ctrl |= (RX8010_CTRL_AIE | RX8010_CTRL_UIE);
> + } else {
> + if (!rx8010->rtc->uie_rtctimer.enabled)
> + ctrl &= ~RX8010_CTRL_UIE;
> + if (!rx8010->rtc->aie_timer.enabled)
> + ctrl &= ~RX8010_CTRL_AIE;
> + }
> +
> + err = rx8010_read_reg(client, RX8010_FLAG, &flagreg);
> + if (err)
> + return err;
> + flagreg &= ~RX8010_FLAG_AF;
> + err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);
> + if (err < 0)
> + return err;
> +
> + if (ctrl != rx8010->ctrlreg) {
> + rx8010->ctrlreg = ctrl;
> + err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
> + rx8010->ctrlreg);
> + if (err < 0)
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct rx8010_data *rx8010 = dev_get_drvdata(dev);
> + int ret, tmp;
> + u8 flagreg;
> + unsigned long irqflags;
> +
> + switch (cmd) {
> + case RTC_VL_READ:
> + ret = rx8010_read_reg(rx8010->client, RX8010_FLAG, &flagreg);
> + if (ret)
> + return ret;
> +
> + tmp = !!(flagreg & RX8010_FLAG_VLF);
> + if (copy_to_user((void __user *)arg, &tmp, sizeof(int)))
> + return -EFAULT;
> +
> + return 0;
> +
> + case RTC_VL_CLR:
> + spin_lock_irqsave(&rx8010->flags_lock, irqflags);
> + ret = rx8010_read_reg(rx8010->client, RX8010_FLAG, &flagreg);
> + if (ret < 0) {
> + spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
> + return ret;
> + }
> +
> + flagreg &= ~RX8010_FLAG_VLF;
> + ret = i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);
> + spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
> + if (ret < 0)
> + return ret;
> +
> + return 0;
> +
> + default:
> + return -ENOIOCTLCMD;
> + }
> +}
> +
> +static struct rtc_class_ops rx8010_rtc_ops = {
> + .read_time = rx8010_get_time,
> + .set_time = rx8010_set_time,
> + .ioctl = rx8010_ioctl,
> +};
> +
> +static int rx8010_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
> + struct rx8010_data *rx8010;
> + int err = 0;
> +
> + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
> + | I2C_FUNC_SMBUS_I2C_BLOCK)) {
> + dev_err(&adapter->dev, "doesn't support required functionality\n");
> + return -EIO;
> + }
> +
> + rx8010 = devm_kzalloc(&client->dev, sizeof(struct rx8010_data),
> + GFP_KERNEL);
> + if (!rx8010)
> + return -ENOMEM;
> +
> + rx8010->client = client;
> + i2c_set_clientdata(client, rx8010);
> +
> + spin_lock_init(&rx8010->flags_lock);
> +
> + err = rx8010_init_client(client);
> + if (err)
> + return err;
> +
> + if (client->irq > 0) {
> + dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
> + err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
> + rx8010_irq_1_handler, IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> + "rx8010", client);
> +
> + if (err) {
> + dev_err(&client->dev, "unable to request IRQ\n");
> + client->irq = 0;
> + } else {
> + rx8010_rtc_ops.read_alarm = rx8010_read_alarm;
> + rx8010_rtc_ops.set_alarm = rx8010_set_alarm;
> + rx8010_rtc_ops.alarm_irq_enable = rx8010_alarm_irq_enable;
> + }
> + }
> +
> + rx8010->rtc = devm_rtc_device_register(&client->dev, client->name,
> + &rx8010_rtc_ops, THIS_MODULE);
> +
> + if (IS_ERR(rx8010->rtc)) {
> + dev_err(&client->dev, "unable to register the class device\n");
> + return PTR_ERR(rx8010->rtc);
> + }
> +
> + rx8010->rtc->max_user_freq = 1;
> +
> + return err;
> +}
> +
> +static struct i2c_driver rx8010_driver = {
> + .driver = {
> + .name = "rtc-rx8010",
> + },
> + .probe = rx8010_probe,
> + .id_table = rx8010_id,
> +};
> +
> +module_i2c_driver(rx8010_driver);
> +
> +MODULE_AUTHOR("Akshay Bhat <[email protected]>");
> +MODULE_DESCRIPTION("Epson RX8010SJ RTC driver");
> +MODULE_LICENSE("GPL");
>

2015-12-01 16:11:41

by Alexandre Belloni

[permalink] [raw]
Subject: Re: [PATCH] rtc: Add Epson RX8010SJ RTC driver

Hi,

On 01/12/2015 at 11:00:16 -0500, Akshay Bhat wrote :
> Hi,
>
> Wanted to check if there was any feedback on this patch?
>

I'm planning to review it this week.

--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

2015-12-02 23:41:03

by Alexandre Belloni

[permalink] [raw]
Subject: Re: [PATCH] rtc: Add Epson RX8010SJ RTC driver

On 11/11/2015 at 17:31:58 -0500, Akshay Bhat wrote :
> diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
> new file mode 100644
> index 0000000..9b8bd76
> --- /dev/null
> +++ b/drivers/rtc/rtc-rx8010.c
> @@ -0,0 +1,570 @@
> +/*
> + * Driver for the Epson RTC module RX-8010 SJ
> + *
> + * Copyright(C) Timesys Corporation 2015
> + * Copyright(C) General Electric Company 2015
> + * Copyright(C) SEIKO EPSON CORPORATION 2013. All rights reserved.
> + *
> + * Derived from RX-8025 driver:
> + * Copyright (C) 2009 Wolfgang Grandegger <[email protected]>
> + *
> + * Copyright (C) 2005 by Digi International Inc.
> + * All rights reserved.
> + *
> + * Modified by fengjh at rising.com.cn
> + * <http://lists.lm-sensors.org/mailman/listinfo/lm-sensors>
> + * 2006.11
> + *
> + * Code cleanup by Sergei Poselenov, <[email protected]>
> + * Converted to new style by Wolfgang Grandegger <[email protected]>
> + * Alarm and periodic interrupt added by Dmitry Rakhchev <[email protected]>
> + *

Please remove all those unnecessary copyrights, the original
rx-8025 has been heavily rewritten anyway.

> +static int rx8010_read_reg(struct i2c_client *client, int number, u8 *value)
> +{
> + int ret = i2c_smbus_read_byte_data(client, number);
> +
> + if (ret < 0)
> + return ret;
> +
> + *value = ret;
> + return 0;
> +}

I don't see the benefit of that function, calling
i2c_smbus_read_byte_data directly is more efficient.

> +
> +static int rx8010_read_regs(struct i2c_client *client, int number, u8 length,
> + u8 *values)
> +{
> + int ret = i2c_smbus_read_i2c_block_data(client, number, length, values);
> +
> + if (ret != length)
> + return ret < 0 ? ret : -EIO;
> +
> + return 0;
> +}

Apart from the error handling, I'd say the same for that function.

> +
> +static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)
> +{
> + struct i2c_client *client = dev_id;
> + struct rx8010_data *rx8010 = i2c_get_clientdata(client);
> + u8 flagreg;
> +
> + spin_lock(&rx8010->flags_lock);
> +
> + if (rx8010_read_reg(client, RX8010_FLAG, &flagreg)) {
> + spin_unlock(&rx8010->flags_lock);
> + return IRQ_NONE;
> + }
> +
> + if (flagreg & RX8010_FLAG_VLF)
> + dev_warn(&client->dev, "Frequency stop detected\n");
> +
> + if (flagreg & RX8010_FLAG_TF) {
> + flagreg &= ~RX8010_FLAG_TF;
> + rtc_update_irq(rx8010->rtc, 1, RTC_PF | RTC_IRQF);
> + }
> +
> + if (flagreg & RX8010_FLAG_AF) {
> + flagreg &= ~RX8010_FLAG_AF;
> + rtc_update_irq(rx8010->rtc, 1, RTC_AF | RTC_IRQF);
> + }
> +
> + if (flagreg & RX8010_FLAG_UF) {
> + flagreg &= ~RX8010_FLAG_UF;
> + rtc_update_irq(rx8010->rtc, 1, RTC_UF | RTC_IRQF);
> + }
> +
> + i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);
> +
> + spin_unlock(&rx8010->flags_lock);
> + return IRQ_HANDLED;
> +}
> +
> +static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
> +{
> + struct rx8010_data *rx8010 = dev_get_drvdata(dev);
> + u8 date[7];
> + u8 flagreg;
> + int err;
> +
> + err = rx8010_read_reg(rx8010->client, RX8010_FLAG, &flagreg);
> + if (err)
> + return err;
> +
> + if (flagreg & RX8010_FLAG_VLF) {
> + dev_warn(dev, "Frequency stop detected\n");
> + return -EINVAL;
> + }
> +
> + err = rx8010_read_regs(rx8010->client, RX8010_SEC, 7, date);
> + if (err)
> + return err;
> +
> + dt->tm_sec = bcd2bin(date[RX8010_SEC-RX8010_SEC] & 0x7f);
> + dt->tm_min = bcd2bin(date[RX8010_MIN-RX8010_SEC] & 0x7f);
> + dt->tm_hour = bcd2bin(date[RX8010_HOUR-RX8010_SEC] & 0x3f);
> + dt->tm_mday = bcd2bin(date[RX8010_MDAY-RX8010_SEC] & 0x3f);
> + dt->tm_mon = bcd2bin(date[RX8010_MONTH-RX8010_SEC] & 0x1f) - 1;
> + dt->tm_year = bcd2bin(date[RX8010_YEAR-RX8010_SEC]);
> + dt->tm_wday = bcd2bin(date[RX8010_WDAY-RX8010_SEC] & 0x7f);
> +

This is not the correct value for tm_wday, you should use ffs(), not
that anybody actually cares.

Also, checkpatch --strict complains about missing spaces around those '-'
and a few alignments are not correct, can fix those?


> + if (dt->tm_year < 70)
> + dt->tm_year += 100;
> +

I'd say that we don't care about handling dates before 2000 and that the
range should be 2000-2100 as this is actually the range where the leap
year calculation is correct. Also your are not respecting that in
rx8010_set_time() so setting a date in 2072 will end up reading 1972.

> + return rtc_valid_tm(dt);
> +}
> +
> +static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
> +{
> + struct rx8010_data *rx8010 = dev_get_drvdata(dev);
> + u8 date[7];
> + u8 ctrl, flagreg;
> + int ret;
> + unsigned long irqflags;
> +
> + /* BUG: The HW assumes every year that is a multiple of 4 to be a leap
> + * year. Next time this is wrong is 2100, which will not be a leap
> + * year.
> + */
> +

Then, return -EINVAL if the year is out of the 100-200 range.


> + /* set STOP bit before changing clock/calendar */
> + ret = rx8010_read_reg(rx8010->client, RX8010_CTRL, &ctrl);
> + if (ret)
> + return ret;
> + rx8010->ctrlreg = ctrl | RX8010_CTRL_STOP;
> + ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
> + rx8010->ctrlreg);
> + if (ret < 0)
> + return ret;
> +
> + date[RX8010_SEC-RX8010_SEC] = bin2bcd(dt->tm_sec);
> + date[RX8010_MIN-RX8010_SEC] = bin2bcd(dt->tm_min);
> + date[RX8010_HOUR-RX8010_SEC] = bin2bcd(dt->tm_hour);
> + date[RX8010_MDAY-RX8010_SEC] = bin2bcd(dt->tm_mday);
> + date[RX8010_MONTH-RX8010_SEC] = bin2bcd(dt->tm_mon + 1);
> + date[RX8010_YEAR-RX8010_SEC] = bin2bcd(dt->tm_year % 100);
> + date[RX8010_WDAY-RX8010_SEC] = bin2bcd(dt->tm_wday);

this is not the expected value for RX8010_WDAY, it must be 1 <<
dt->tm_wday, see the datasheet.

> +
> + ret = i2c_smbus_write_i2c_block_data(rx8010->client,
> + RX8010_SEC, 7, date);
> + if (ret < 0)
> + return ret;
> +
> + /* clear STOP bit after changing clock/calendar */
> + ret = rx8010_read_reg(rx8010->client, RX8010_CTRL, &ctrl);
> + if (ret)
> + return ret;
> + rx8010->ctrlreg = ctrl & ~RX8010_CTRL_STOP;
> + ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
> + rx8010->ctrlreg);
> + if (ret < 0)
> + return ret;
> +
> + spin_lock_irqsave(&rx8010->flags_lock, irqflags);
> +
> + ret = rx8010_read_reg(rx8010->client, RX8010_FLAG, &flagreg);
> + if (ret) {
> + spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
> + return ret;
> + }
> +
> + if (flagreg & RX8010_FLAG_VLF)
> + ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG,
> + flagreg & ~RX8010_FLAG_VLF);
> +
> + spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
> +
> + return 0;
> +}
> +
> +static int rx8010_init_client(struct i2c_client *client)
> +{
> + struct rx8010_data *rx8010 = i2c_get_clientdata(client);
> + u8 ctrl[3];
> + int need_clear = 0, need_reset = 0, err = 0;
> +
> + /* Initialize reserved registers as specified in datasheet */
> + err = i2c_smbus_write_byte_data(client, RX8010_RESV17, 0xD8);
> + if (err < 0)
> + return err;
> +
> + err = i2c_smbus_write_byte_data(client, RX8010_RESV30, 0x00);
> + if (err < 0)
> + return err;
> +
> + err = i2c_smbus_write_byte_data(client, RX8010_RESV31, 0x08);
> + if (err < 0)
> + return err;
> +
> + err = i2c_smbus_write_byte_data(client, RX8010_IRQ, 0x00);
> + if (err < 0)
> + return err;
> +
> + err = rx8010_read_regs(rx8010->client, RX8010_EXT, 3, ctrl);
> + if (err)
> + return err;
> +
> + if ((ctrl[1] & RX8010_FLAG_VLF)) {
> + dev_warn(&client->dev, "Frequency stop was detected\n");
> + need_reset = 1;
> + }
> +
> + if (ctrl[1] & RX8010_FLAG_AF) {
> + dev_warn(&client->dev, "Alarm was detected\n");
> + need_clear = 1;
> + }
> +
> + if (ctrl[1] & RX8010_FLAG_TF)
> + need_clear = 1;
> +
> + if (ctrl[1] & RX8010_FLAG_UF)
> + need_clear = 1;
> +
> + if (need_reset) {
> + ctrl[0] = ctrl[1] = ctrl[2] = 0;
> + err = i2c_smbus_write_i2c_block_data(client, RX8010_EXT,
> + 3, ctrl);
> + if (err < 0)
> + return err;

Please don't do that, reseting RX8010_FLAG_VLF will make userspace
believe that the bogus date is valid.

> + } else if (need_clear) {
> + err = i2c_smbus_write_byte_data(client, RX8010_FLAG, 0x00);
> + if (err < 0)
> + return err;
> + }
> +
> + rx8010->ctrlreg = (ctrl[2] & ~RX8010_CTRL_TEST);
> +

BTW, I'm not sure about the necessity to cache ctrl. It actually only saves one
i2c read in the alarm functions.

> + return err;
> +}
> +


--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

2015-12-03 19:49:37

by Akshay Bhat

[permalink] [raw]
Subject: Re: [PATCH] rtc: Add Epson RX8010SJ RTC driver

Thanks for the detailed feedback and mentioning --strict option for
checkpatch :) I have fixed all the issues in the v2 version of the
patch: https://lkml.org/lkml/2015/12/3/606

On 12/02/2015 06:40 PM, Alexandre Belloni wrote:
> On 11/11/2015 at 17:31:58 -0500, Akshay Bhat wrote :
>> diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
>> new file mode 100644
>> index 0000000..9b8bd76
>> --- /dev/null
>> +++ b/drivers/rtc/rtc-rx8010.c
>> @@ -0,0 +1,570 @@
>> +/*
>> + * Driver for the Epson RTC module RX-8010 SJ
>> + *
>> + * Copyright(C) Timesys Corporation 2015
>> + * Copyright(C) General Electric Company 2015
>> + * Copyright(C) SEIKO EPSON CORPORATION 2013. All rights reserved.
>> + *
>> + * Derived from RX-8025 driver:
>> + * Copyright (C) 2009 Wolfgang Grandegger <[email protected]>
>> + *
>> + * Copyright (C) 2005 by Digi International Inc.
>> + * All rights reserved.
>> + *
>> + * Modified by fengjh at rising.com.cn
>> + * <http://lists.lm-sensors.org/mailman/listinfo/lm-sensors>
>> + * 2006.11
>> + *
>> + * Code cleanup by Sergei Poselenov, <[email protected]>
>> + * Converted to new style by Wolfgang Grandegger <[email protected]>
>> + * Alarm and periodic interrupt added by Dmitry Rakhchev <[email protected]>
>> + *
>
> Please remove all those unnecessary copyrights, the original
> rx-8025 has been heavily rewritten anyway.
>
>> +static int rx8010_read_reg(struct i2c_client *client, int number, u8 *value)
>> +{
>> + int ret = i2c_smbus_read_byte_data(client, number);
>> +
>> + if (ret < 0)
>> + return ret;
>> +
>> + *value = ret;
>> + return 0;
>> +}
>
> I don't see the benefit of that function, calling
> i2c_smbus_read_byte_data directly is more efficient.
>
>> +
>> +static int rx8010_read_regs(struct i2c_client *client, int number, u8 length,
>> + u8 *values)
>> +{
>> + int ret = i2c_smbus_read_i2c_block_data(client, number, length, values);
>> +
>> + if (ret != length)
>> + return ret < 0 ? ret : -EIO;
>> +
>> + return 0;
>> +}
>
> Apart from the error handling, I'd say the same for that function.
>
>> +
>> +static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)
>> +{
>> + struct i2c_client *client = dev_id;
>> + struct rx8010_data *rx8010 = i2c_get_clientdata(client);
>> + u8 flagreg;
>> +
>> + spin_lock(&rx8010->flags_lock);
>> +
>> + if (rx8010_read_reg(client, RX8010_FLAG, &flagreg)) {
>> + spin_unlock(&rx8010->flags_lock);
>> + return IRQ_NONE;
>> + }
>> +
>> + if (flagreg & RX8010_FLAG_VLF)
>> + dev_warn(&client->dev, "Frequency stop detected\n");
>> +
>> + if (flagreg & RX8010_FLAG_TF) {
>> + flagreg &= ~RX8010_FLAG_TF;
>> + rtc_update_irq(rx8010->rtc, 1, RTC_PF | RTC_IRQF);
>> + }
>> +
>> + if (flagreg & RX8010_FLAG_AF) {
>> + flagreg &= ~RX8010_FLAG_AF;
>> + rtc_update_irq(rx8010->rtc, 1, RTC_AF | RTC_IRQF);
>> + }
>> +
>> + if (flagreg & RX8010_FLAG_UF) {
>> + flagreg &= ~RX8010_FLAG_UF;
>> + rtc_update_irq(rx8010->rtc, 1, RTC_UF | RTC_IRQF);
>> + }
>> +
>> + i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);
>> +
>> + spin_unlock(&rx8010->flags_lock);
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
>> +{
>> + struct rx8010_data *rx8010 = dev_get_drvdata(dev);
>> + u8 date[7];
>> + u8 flagreg;
>> + int err;
>> +
>> + err = rx8010_read_reg(rx8010->client, RX8010_FLAG, &flagreg);
>> + if (err)
>> + return err;
>> +
>> + if (flagreg & RX8010_FLAG_VLF) {
>> + dev_warn(dev, "Frequency stop detected\n");
>> + return -EINVAL;
>> + }
>> +
>> + err = rx8010_read_regs(rx8010->client, RX8010_SEC, 7, date);
>> + if (err)
>> + return err;
>> +
>> + dt->tm_sec = bcd2bin(date[RX8010_SEC-RX8010_SEC] & 0x7f);
>> + dt->tm_min = bcd2bin(date[RX8010_MIN-RX8010_SEC] & 0x7f);
>> + dt->tm_hour = bcd2bin(date[RX8010_HOUR-RX8010_SEC] & 0x3f);
>> + dt->tm_mday = bcd2bin(date[RX8010_MDAY-RX8010_SEC] & 0x3f);
>> + dt->tm_mon = bcd2bin(date[RX8010_MONTH-RX8010_SEC] & 0x1f) - 1;
>> + dt->tm_year = bcd2bin(date[RX8010_YEAR-RX8010_SEC]);
>> + dt->tm_wday = bcd2bin(date[RX8010_WDAY-RX8010_SEC] & 0x7f);
>> +
>
> This is not the correct value for tm_wday, you should use ffs(), not
> that anybody actually cares.
>
> Also, checkpatch --strict complains about missing spaces around those '-'
> and a few alignments are not correct, can fix those?
>
>
>> + if (dt->tm_year < 70)
>> + dt->tm_year += 100;
>> +
>
> I'd say that we don't care about handling dates before 2000 and that the
> range should be 2000-2100 as this is actually the range where the leap
> year calculation is correct. Also your are not respecting that in
> rx8010_set_time() so setting a date in 2072 will end up reading 1972.
>
>> + return rtc_valid_tm(dt);
>> +}
>> +
>> +static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
>> +{
>> + struct rx8010_data *rx8010 = dev_get_drvdata(dev);
>> + u8 date[7];
>> + u8 ctrl, flagreg;
>> + int ret;
>> + unsigned long irqflags;
>> +
>> + /* BUG: The HW assumes every year that is a multiple of 4 to be a leap
>> + * year. Next time this is wrong is 2100, which will not be a leap
>> + * year.
>> + */
>> +
>
> Then, return -EINVAL if the year is out of the 100-200 range.
>
>
>> + /* set STOP bit before changing clock/calendar */
>> + ret = rx8010_read_reg(rx8010->client, RX8010_CTRL, &ctrl);
>> + if (ret)
>> + return ret;
>> + rx8010->ctrlreg = ctrl | RX8010_CTRL_STOP;
>> + ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
>> + rx8010->ctrlreg);
>> + if (ret < 0)
>> + return ret;
>> +
>> + date[RX8010_SEC-RX8010_SEC] = bin2bcd(dt->tm_sec);
>> + date[RX8010_MIN-RX8010_SEC] = bin2bcd(dt->tm_min);
>> + date[RX8010_HOUR-RX8010_SEC] = bin2bcd(dt->tm_hour);
>> + date[RX8010_MDAY-RX8010_SEC] = bin2bcd(dt->tm_mday);
>> + date[RX8010_MONTH-RX8010_SEC] = bin2bcd(dt->tm_mon + 1);
>> + date[RX8010_YEAR-RX8010_SEC] = bin2bcd(dt->tm_year % 100);
>> + date[RX8010_WDAY-RX8010_SEC] = bin2bcd(dt->tm_wday);
>
> this is not the expected value for RX8010_WDAY, it must be 1 <<
> dt->tm_wday, see the datasheet.
>
>> +
>> + ret = i2c_smbus_write_i2c_block_data(rx8010->client,
>> + RX8010_SEC, 7, date);
>> + if (ret < 0)
>> + return ret;
>> +
>> + /* clear STOP bit after changing clock/calendar */
>> + ret = rx8010_read_reg(rx8010->client, RX8010_CTRL, &ctrl);
>> + if (ret)
>> + return ret;
>> + rx8010->ctrlreg = ctrl & ~RX8010_CTRL_STOP;
>> + ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
>> + rx8010->ctrlreg);
>> + if (ret < 0)
>> + return ret;
>> +
>> + spin_lock_irqsave(&rx8010->flags_lock, irqflags);
>> +
>> + ret = rx8010_read_reg(rx8010->client, RX8010_FLAG, &flagreg);
>> + if (ret) {
>> + spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
>> + return ret;
>> + }
>> +
>> + if (flagreg & RX8010_FLAG_VLF)
>> + ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG,
>> + flagreg & ~RX8010_FLAG_VLF);
>> +
>> + spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
>> +
>> + return 0;
>> +}
>> +
>> +static int rx8010_init_client(struct i2c_client *client)
>> +{
>> + struct rx8010_data *rx8010 = i2c_get_clientdata(client);
>> + u8 ctrl[3];
>> + int need_clear = 0, need_reset = 0, err = 0;
>> +
>> + /* Initialize reserved registers as specified in datasheet */
>> + err = i2c_smbus_write_byte_data(client, RX8010_RESV17, 0xD8);
>> + if (err < 0)
>> + return err;
>> +
>> + err = i2c_smbus_write_byte_data(client, RX8010_RESV30, 0x00);
>> + if (err < 0)
>> + return err;
>> +
>> + err = i2c_smbus_write_byte_data(client, RX8010_RESV31, 0x08);
>> + if (err < 0)
>> + return err;
>> +
>> + err = i2c_smbus_write_byte_data(client, RX8010_IRQ, 0x00);
>> + if (err < 0)
>> + return err;
>> +
>> + err = rx8010_read_regs(rx8010->client, RX8010_EXT, 3, ctrl);
>> + if (err)
>> + return err;
>> +
>> + if ((ctrl[1] & RX8010_FLAG_VLF)) {
>> + dev_warn(&client->dev, "Frequency stop was detected\n");
>> + need_reset = 1;
>> + }
>> +
>> + if (ctrl[1] & RX8010_FLAG_AF) {
>> + dev_warn(&client->dev, "Alarm was detected\n");
>> + need_clear = 1;
>> + }
>> +
>> + if (ctrl[1] & RX8010_FLAG_TF)
>> + need_clear = 1;
>> +
>> + if (ctrl[1] & RX8010_FLAG_UF)
>> + need_clear = 1;
>> +
>> + if (need_reset) {
>> + ctrl[0] = ctrl[1] = ctrl[2] = 0;
>> + err = i2c_smbus_write_i2c_block_data(client, RX8010_EXT,
>> + 3, ctrl);
>> + if (err < 0)
>> + return err;
>
> Please don't do that, reseting RX8010_FLAG_VLF will make userspace
> believe that the bogus date is valid.
>
>> + } else if (need_clear) {
>> + err = i2c_smbus_write_byte_data(client, RX8010_FLAG, 0x00);
>> + if (err < 0)
>> + return err;
>> + }
>> +
>> + rx8010->ctrlreg = (ctrl[2] & ~RX8010_CTRL_TEST);
>> +
>
> BTW, I'm not sure about the necessity to cache ctrl. It actually only saves one
> i2c read in the alarm functions.
>
>> + return err;
>> +}
>> +
>
>